Aircurve VAuto PS...pros & cons

[WW4B]

What are the advantages and/or disadvantages of increasing pressure support on a Aircurve Vauto 10/11. Will a higher PS cause co2 issues. When do stop increasing PS in regards to controlling flow limits. What is considered too high of a PS.

[SarcasticDave94]

The settings somewhat are dependent on the individual. PS typically it's set between 3-5, sometimes a bit more but rarely that I've seen.

Higher PS can cause CO2 flushing that in turn may cause Central Apnea.

Low PS might not have enough pressure differential between exhale to inhale. Too high, and again it may cause CA.

[WW4B]

SarcasticDave, thanks for the reply. I have been reading and questioning my PS, flow limits, Tidal Volume and respiration rates lately. I have noticed that it feels like that there is a pause in my breathing at the end of my exhale and before IPAP. In spite of "good numbers" I am always feeling fatigued and not sharp during the day. Have been wondering if Co2 is playing a role in my tiredness and brain fog. Am I over-ventilated by using a PS of 6. I started with a PS of 4 and slowly increased PS to get my flow limits down. What does the attached chart indicate. Any advice ?
   

[SarcasticDave94]

I'd drop PS to 5 and see how that goes. It's showing 5.8, and while you're treated, it might be just a bit much. Currently Flow Limit is great on this chart.

[WW4B]

Thank you again...
PS was set at 6 but backed it off last night to 5.8 and was considering continuing backing off to get back down to 5. At PS 5 my 95% flow limits were usually over .07. Titrated up to PS/6 and flow limits went down. I am 5'10 @ 250 lbs in relatively good shape. Do you believe my TV is on the high side ? I am thinking my tiredness might be a co2 issue. What can or should I try. Would the PS of 6 cause a co2 issue. Developed CA's when titrating PS upwards but set trigger to high and in time CA's for the most part went away. When they do appear I believe it is because of breath holding at the end of my exhale...what would cause this. 
I just had an in lab sleep study where they recommended EPAP 10 - IPAP 15, but I never really needed a EPAP of more than 8-9 to treat OA & H. Do you believe PS of 6 is doing more harm than good ?

[THEVGE]

I optimized my therapy looking at nice rounded tops of my inhale. Can you share a zoom-in of how that looks for you? I feel your flow rate looks very unstable but without a zoom in it is hard to judge what is happening. A few 3 minute blocks would help.

I currently use PS 5,6 so I am one of those rarer cases. My inspiration flow rate becomes decent only after PS 5,0 and even now I think 5,8 or even 6,0 would be better for me as I still suffer from RERA's (and also verified with WatchPAT). As you I am a bit worried about CO2 issues as I also have other issues without clear cause and my sleep is still not great.

[SarcasticDave94]

The PS 6 seems to be about your threshold on CO2 flushing from your info. That is what will trigger the CA for you.

If you feel you need something like PS 6, you might combine that with very high Trigger.

Higher PS begins to get ventilator like properties to a degree. Higher PS leverages more on the inhale, and in turn exhale causes more CO2 to be evacuated. This will upset your nervous system to sense the imbalance, breath pauses are added attempting to compensate, and gets CA flagged.

[WW4B]

SarcasticDave, thank you for looking into my posts...I am very grateful. Attached are last nights chart with 2 zoomed in three minute segments as you requested from last nights chart of which PS was dropped to 5.6. Would love to hear your thoughts and insight on what these zoomed segments may or may not indicate. Had my appt with the pulmonologist today and other than the Dr. saying your numbers look okay you are doing fine, stay the course. What a waste of a copay !
Should have my in lab sleep report soon which I can/will post if interested. Would you further pursue dropping PS? Looking forward to your reply on what your trained eyes perceive. Again, thank you.
Like you, definitely drinking coffee in PA (Bucks County area)
   
   
   

[SarcasticDave94]

It looks pretty good as is. How did the therapy feel? If you were good, keep it a few days and review.

[WW4B]

Therapy felt okay. I had no problem throughout the night other than I do remember my dreams. Did still feel tired once awake and could have (wanted to) go back to sleep but had to get up. I will post my sleep study tomorrow and would appreciate your opinion and if my now titrated therapy results supports the sleep study findings. I still think I may be over titrated. Just for comparison, attached is a chart from early October with a PS of 5. Whats the difference ????